A lighting device for vehicles is known from EP 2 065 635 B1, having a flat optical fiber, wherein a plurality of light sources on a light coupling side are functionally assigned to said flat optical fiber. The optical fiber has a flat segment with opposing flat sides, wherein the light which has been input is relayed toward a light decoupling area. The light decoupling area is designed on narrow side. A plurality of finger-shaped light coupling elements project from a narrow side opposite the light decoupling area, and form a light coupling area on a free end. The light sources can be arranged on a single shared, rigid circuit board which runs parallel to the level of extension of the optical fiber. Deflection means are included between the light coupling area and the flat segment of the optical fiber, such that the light can be deflected substantially by 90°, toward the light decoupling area. As a result of the fact that the light sources are always arranged in a single shared plane, it is not possible to optimally take advantage of the limited constructed space of a headlight.